[show abstract][hide abstract] ABSTRACT: An 87-year-old woman visited our clinic for a scheduled cataract surgery. At the time of preoperative evaluation, slit lamp examination showed lattice-shaped and granular deposits with asymmetrical patterns in the stroma of both corneas. Genomic DNA samples of the patient, amplified by polymerase chain reaction, showed a single nucleotide substitution, c. 1580T>G (p.L527R), in the transforming growth factor-β-induced TGFBI gene. We also found two additional SNP mutations, c.1620T>C (p.F540F) and c.1678+23G>A, along with the well-known L527R mutation. This is the first report of lattice corneal dystrophy type IV with an L527R mutation outside of Japan, and could challenge the idea that L527R is caused by a mutation from a single Japanese ancestor.
Korean Journal of Ophthalmology 02/2014; 28(1):83-5.
[show abstract][hide abstract] ABSTRACT: To develop a high flux and high power density the polyethersulfone (PES) membrane support was modified by coating with polydopamine (PDA), based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under mild conditions. After polydopamine coating the effect of thin film composite (TFC) on polydopamine layer was studied. The surface morphological changes were characterized using SEM. The influence of the modifying conditions such as coating time and DA concentration on the membrane properties was investigated. It was found that the most reasonable modification conditions to obtain the high power density performance are 0.2 g/l DA concentration with 1 h coating time. After PDA coating the TFC active layer was prepare on the surface of coated membrane. There was tremendous increment of the flux for the polydopamine coated thin film composite (PDA-TFC) membrane under the best conditions compared with that of the original membrane (PES substrate). The result showed that the PDA-TFC membrane has higher flux, excellent power density performance and good stability. The results by using these membranes were promising, indicating that the modified membranes exhibited an increase in flux performance under testing conditions when compared to baseline control data. This modification method, which is scalable, has the potential to enable the use of existing thin film composite membranes for all engineered osmosis applications. This work provides a simple method of modifying PES membrane for better performance and potential application in pressure retarded osmosis (PRO).
Chemical Engineering Journal 01/2014; · 3.47 Impact Factor
[show abstract][hide abstract] ABSTRACT: Landfill gas is major source of green house effect because it is mainly composed of CH4 and CO2. Especially, the separation of CH4 from landfill gas was studied actively due to its high heating value which can be used for energy resource. In this study, polymeric hollow fiber membrane was produced by dry–wet phase inversion method to separate CH4 from the landfill gas. The morphology of the membranes was examined by scanning electron microscopy (SEM) to understand and correlate the morphology with the performance of the membrane. Firstly, single gas permeation and mixed gas separation were performed in lab-scale. After then, a pilot scale membrane process was designed using a simulation program. The manufactured process settled in Gyeong-ju landfill site and operated at various conditions. As a result, CH4 was concentrated to 88 vol.% and also CO2 removal efficiency increases up to 86.7%.
[show abstract][hide abstract] ABSTRACT: Abstract Purpose: To measure the expression level and pattern of neurotrophic factors and their receptors in keratoconus (KC) cornea using quantitative RT-PCR (qPCR) and immunostaining. Materials and Methods: Twenty-one recipient corneal buttons after keratoplasty from KC cornea and four age-matched normal corneas were obtained. The 25 corneal tissues were divided into two pieces; one fragment of each sample was used for immunostaining whereas the other fragment was used for qPCR. Using primary antibodies and specific qPCR primer, immunostaining and qPCR were performed to analyze the expression level of the neurotrophic factors and receptors. Results: Nerve growth factor and its receptors (TrkA and p75NTR) were not expressed in the center of normal cornea. However, TrkA and the p75NTR were clearly expressed in a membrane bound staining pattern and the mRNA levels were significantly higher in KC (p < 0.001). The mRNA expression of brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and neurotrophin (NT)-4 mRNA was also elevated in KC (p < 0.001). BDNF was expressed in epithelium of normal cornea. However, in KC, its expression was found to be extending into the anterior stromal layer. CNTF was hardly expressed in normal cornea. In KC, the entire epithelium expressed CNTF, especially in perinuclear area. NT-4 was expressed throughout the epithelium and stroma in KC. Conclusion: The change in expression of neurotrophic factors in KC may suggest that these factors play an important role in the pathogenesis of KC and serve as new markers for the progression of KC.
Current eye research 03/2013; · 1.51 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the predictability of various intraocular lens (IOL) power calculation methods in granular corneal dystrophy type 2 (GCD2) with prior phototherapeutic keratectomy (PTK) and to suggest the more predictable IOL power calculation method.
Medical records of 20 eyes from 16 patients with GCD2, all having undergone cataract surgery after PTK, were retrospectively evaluated. Postoperative cataract refractive errors were compared with target diopters (D) using IOL power calculation methods as follows: 1) myopic and 2) hyperopic Haigis-L formula in IOLMaster (Carl Zeiss Meditec); 3) SRK/T formula using 4.5-mm zone Holladay equivalent keratometry readings (EKRs) (single-K Holladay EKRs method); 4) central keratometry power of true net power map in the Pentacam system (Oculus Optikgeräte GmbH); and 5) clinical history, Aramberri double-K, and double-K Holladay EKRs methods. Topographic status of corneal curvature after PTK was evaluated.
Fourteen (70%) of 20 eyes showed central island formation after PTK. When central island was present, the mean absolute error (MAE) using the hyperopic Haigis-L formula was 0.25±0.15 D. When central island was not present, the myopic Haigis-L formula showed MAE of 0.33±0.16 D. When central island formation and IOLMaster keratometry underestimation were present, the hyperopic Haigis-L formula showed the least MAE of 0.26±0.08 D when switching the IOL-Master keratometry values equal to 4.5-mm zone Holladay EKRs.
In planning for cataract surgery after PTK in GCD2, topographic analysis for central island formation is necessary. With or without central island formation, the hyperopic or myopic Haigis-L formula can be applied. When IOLMaster keratometry shows underestimation, the Haigis-L formula using 4.5-mm zone Holladay EKRs can be considered.
Journal of refractive surgery (Thorofare, N.J.: 1995) 10/2012; 28(10):714-24. · 2.47 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVE: To investigate the expression level of prostaglandins (PGs) and their de novo synthesis in dry eye (DE) disease. DESIGN: Cross-sectional case-control study and in vivo mouse experimental study. PARTICIPANTS: Forty-six eyes from 23 DE patients and 33 eyes from 17 age- and sex-matched controls were studied. Also, DE-induced murine eyes were compared with control eyes. METHODS: Patients completed a symptom questionnaire using a 100-mm visual analog scale (VAS). Nano-liquid chromatography tandem mass spectrometry was used for the quantification of PGE2 and PGD2. A DE disease environmental chamber was used to induce DE in mice. One week after induction, enzyme expressions of cyclooxygenase-1, cyclooxygenase-2 (COX-2), PG E synthase (PGES), and PG D synthase (PGDS) in the lacrimal glands, meibomian glands, and corneas were examined using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). MAIN OUTCOME MEASURES: The mean PGE2 and PGD2 levels in the tears of DE patients were measured and compared with symptom severity scores. Immunohistochemistry staining patterns and qRT-PCR data of DE mice were quantified. RESULTS: The mean PGE2 level in the tears of DE patients (2.72±3.42 ng/ml) was significantly higher than that in the control group (0.88±0.83 ng/ml; P = 0.003). However, the mean PGD2 level in the tears of DE patients (0.11±0.22 ng/ml) was significantly lower (0.91±3.28 ng/ml; P = 0.028). The mean PGE2-to-PGD2 ratio correlated strongly with VAS scoring (P = 0.008). In DE mice, COX-2 mRNA was significantly higher in ocular surface tissue and lacrimal glands. Furthermore, PGES mRNA was significantly higher in ocular surface tissue, whereas PGDS mRNA was decreased. Immunohistochemistry staining showed elevated COX-2 expression in the lacrimal glands, meibomian glands, corneas, and conjunctivas. Furthermore, PGES expression was found in periductal infiltrated cells of the lacrimal glands and conjunctival epithelium. Also, PGDS expression was decreased in meibomian glands and increased focally in the conjunctival epithelium. CONCLUSIONS: A reciprocal change in PGE2 and PGD2 levels was found in the tears of DE patients, which correlated with patients' symptom scores. These clinical results were supported by increased COX-2 and PGES expression levels found in tear-producing tissues of DE mice. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
[show abstract][hide abstract] ABSTRACT: Included in biogas, methane (CH4) could be used as one of the important energy sources. In this research, membrane separation process took place to recover purified CH4, such as hydrogen sulfide (H2S). The Polyethersulfone (PES) Hollow Fiber Membranes (HFM) was prepared by the dry-wet phase inversion technique. The simulation program using MATLAB was evaluated by utilizing the information from experimental results of a well-designed process. From the simulation program, the process that meets the specified conditions was designed. The three-stage process that has membrane area of 454.3 m recovered 91.3% of CH4 in the feed of 250 l/min at 5 kgf/cm and 30 °C. The membrane area and the recovery of CH4 decreases as the operating process increases.
Separation Science and Technology - SEPAR SCI TECHNOL. 01/2012;
[show abstract][hide abstract] ABSTRACT: This study investigated the effects of the tumor suppressor protein PTEN (phosphatase and tensin homolog) on transforming growth factor (TGF)-β1-mediated signaling pathways and the transdifferentiation of human subconjunctival fibroblasts (SCFs) after the transduction of this protein containing a transactivator of transcription (Tat) domain.
The Tat-PTEN expression vector was constructed to express the Tat domain of HIV-1 fused to PTEN. After transduction of the fusion protein and TGF-β1 stimulation, the dose-dependent effect of the transduced Tat-PTEN fusion protein on Akt phosphorylation and the stability of the Tat-PTEN fusion protein in SCF cells were evaluated by Western blot analysis. The effect of the Tat-PTEN fusion protein on the TGF-β1-stimulated expression of α-SMA and fibronectin was also evaluated by Western blot analysis and immunocytochemistry.
To increase the efficiency of enzyme activity and to successfully deliver this protein to cells, the authors used a PTEN fusion protein that contained the transduction domain of the Tat protein from HIV-1. By Western blot analysis, the transduced Tat-PTEN fusion protein was found to modulate TGF-β1 signaling in SCF cells and result in the suppression of Akt phosphorylation. Furthermore, the transduction of the Tat-PTEN fusion protein was found to suppress the TGF-β1-stimulated expression of α-SMA and fibronectin by Western blot analysis and immunocytochemical staining, and the effects of the transduced fusion protein could be controlled in a dose-dependent manner.
The Tat-PTEN fusion proteins were successfully transduced into the SCF cells and induced the suppression of transdifferentiation and fibrosis through the regulation of TGF-β-mediated signaling. The ability of the Tat-PTEN fusion protein to regulate cell survival could potentially be applied to protein therapy to counteract postoperative scarring in glaucoma surgery.
[show abstract][hide abstract] ABSTRACT: We investigated the effects of cyclosporine A (CsA) on the mechanism of nerve growth factor (NGF) expression using a cultured human corneal epithelial cell line (HCECL).
NGF transcription and production levels were assessed after treatment of cells with various concentrations of CsA. Activities of mitogen-activated protein kinase (MAPK), nuclear factor Kappa B (NF-κB), activator protein-1 (AP-1), and nuclear factor of activated T cells (NFATs) influenced by CsA were determined using a luciferase assay. The translocation activity of NFAT5 was assessed by confocal microscopy and Western immunoblotting after CsA treatment. Transcriptional activity of NGF was measured after pretreatment of cells with SB20429 (a p38 inhibitor) and NFAT5 small interfering RNA.
NGF was induced after treatment with CsA, but not dexamethasone, in the HCECL. NGF expression was mediated via p38 phosphorylation and NFAT5 activation. Transcriptional activities of NF-κB, AP-1, and NFAT1 were not stimulated by CsA; however, nuclear translocation of NFAT5 was markedly upregulated by CsA. CsA-induced NGF production was markedly decreased on inhibition of NFAT5 or SB20429.
CsA is a potent inducer of NGF in the HCECL. These results suggest that CsA mediates NGF expression through activation of p38 and NFAT5.
[show abstract][hide abstract] ABSTRACT: Th17 cells, in addition to their proinflammatory functions, have been recognized as potent inducers of angiogenesis in autoimmune diseases and malignancies. In the present study, we demonstrate distinct mechanisms by which IL-17 induces lymphangiogenesis. Using the mouse cornea micropocket and cell culture assays, our data demonstrate that IL-17 directly promotes growth of lymphatic vessels by inducing increased expression of prolymphangiogenic VEGF-D and proliferation of lymphatic endothelial cells. However, IL-17-induced growth of blood vessels is primarily mediated through IL-1β secretion by IL-17-responsive cells. Furthermore, in vivo blockade of IL-17 in a preclinical model of Th17-dominant autoimmune ocular disease demonstrates a significant reduction in the corneal lymphangiogenesis and in the progression of clinical disease. Taken together, our findings demonstrate a novel prolymphangiogenic function for Th17/IL-17, indicating that IL-17 can promote the progression and amplification of immunity in part through its induction of lymphangiogenesis.
[show abstract][hide abstract] ABSTRACT: Protein tyrosine kinase 7 (PTK7) is a pseudokinase whose precise function in regulating angiogenesis remains unknown. The purpose of this study was to define the mechanisms by which PTK7 promotes vascular endothelial growth factor-A (VEGF-A)-induced angiogenesis in vivo and in vitro. Immunoblotting was used to measure PTK7 expression in several types of vascular endothelial cells. Using both immunoprecipitation and immunoblotting, PTK7 was found to join a receptor complex with Flt-1 (VEGFR1), but not with KDR/Flk-1 (VEGFR2) or with Flt-4 (VEGFR3). By surface plasmon resonance analysis, the interaction between Flt-1 and PTK7 was confirmed and found to be intensified by VEGF-A. Flt-1 phosphorylation and downstream signals of Akt, and focal adhesion kinase (FAK) thus induced were down-regulated by inhibition of PTK7 expression using siRNA. Moreover, PTK7 overexpression in endothelial cells resulted in enhanced angiogenesis in vitro. In contrast, neovascularization induced in vivo by VEGF-A pellets was significantly decreased by injection of siRNA targeting PTK7. These data suggest that PTK7 serves an essential role in Flt-1-mediated angiogenesis.
[show abstract][hide abstract] ABSTRACT: To compare the reliability and the agreement in measuring central corneal thickness (CCT) using the following technologies: RTVue Fourier-domain optical coherence tomography (Optovue, Inc., Fremont, CA), Pentacam (Oculus, Inc., Wetzlar, Germany), and ultrasonic pachymetry (USP; Pocket-II; Quantel Medical, Inc., Bozeman, MT).
Evaluation of diagnostic test.
One hundred four eyes of 52 healthy subjects (mean age ± standard deviation, 28.6 ± 4.8 years).
One eye from each subject was assigned randomly for a repeatability test in which a single operator performed 3 successive measurements. The other eye underwent an interoperator reproducibility test by 3 operators. Two centering methods of RTVue and 3 types of CCT from Pentacam were investigated. For USP, 1 drop of topical anesthetic was administered, and measurement was initiated 90 seconds later. Agreement among the instruments was evaluated using Bland-Altman plots.
Various types of CCT were compared: central zone average and minimum thickness of RTVue centering on the vertex and the pupil; corneal thickness at the pupil center, apex, and thinnest location from Pentacam; and mean CCT of 5 repeated measurements of USP. The reliability of measurement was assessed using the repeatability or reproducibility coefficient (Rco), the coefficient of variation, and the intraclass correlation coefficient. The limit of agreement was used to analyze concordance.
The Rco of RTVue was 4 to 5 μm, which was comparable with that of USP and better than that of Pentacam (10-11 μm). The Rco was not dependent on centering methods (RTVue) or types of CCT (Pentacam). The location of minimum thickness found by RTVue was less reliable than that of the Pentacam. The central zone average of RTVue was approximately 7 μm larger than the pupil center or apex thickness of Pentacam and approximately 13 μm larger than the CCT measurement of USP. Those discrepancies could be as high as 20 and 23 μm, respectively. The minimum thickness measured by the RTVue was similar to that of Pentacam.
The RTVue is a rapid and reliable noncontact means of measuring CCT; however, the characteristics of CCT measured by RTVue must be understood when comparing the CCT obtained by the Pentacam or USP.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
[show abstract][hide abstract] ABSTRACT: Purpose. The purpose of this study was to elucidate the pathophysiological process in primary cultured corneal fibroblasts (PCFs) from normal subjects and granular corneal dystrophy (GCD) II patients, by using cDNA microarrays. Methods. PCFs were isolated from the corneas of normal subjects and GCD II patients who were heterozygous and homozygous for the TGFBI R124H mutation. RNA was isolated from each sample, and gene expression profiles were analyzed with a cDNA microarray consisting of approximately 29,000 genes. Cell adhesion assays were performed to confirm the functionality of the detected gene expression profiles. Results. Twofold differences were detected in the expression of 555 genes between wild-type and homozygous GCD II PCFs. Of these, 319 genes were upregulated, and 236 genes were downregulated in the homozygous GCD II PCFs. The most abundant and consistent changes were observed in gene families encoding signal transduction pathways involving the TGF-beta receptor- and integrin-mediated signaling, cell differentiation and proliferation, immune responses, cell adhesion, extracellular matrix (ECM) proteolytic enzymes, cell cycle, cytoskeletal organization, mitochondrial energy metabolism, collagen catabolism, response to wounding, response to oxidative stress, and the ubiquitin-mediated proteasomal degradation pathway. Cell adhesion assays demonstrated that heterozygous and homozygous GCD II PCFs strongly attached to collagen-I, collagen-IV, fibronectin, and laminin, compared with wild-type cells. Conclusions. Alterations in the TGF-beta receptor- and integrin-mediated signaling pathway may play a key role in GCD II pathophysiology. If the novel factors identified in this study are involved in GCD II pathogenesis, they could assist in designing further studies to elucidate specific mechanisms of this disease.
[show abstract][hide abstract] ABSTRACT: Granular corneal dystrophy type II (GCD II) is an autosomal dominant disorder characterized by age-dependent progressive accumulation of transforming growth factor-beta-induced protein (TGFBIp) deposits in the corneal stroma. Several studies have suggested that corneal fibroblasts may decline with age in response to oxidative stress. To investigate whether oxidative stress is involved in the pathogenesis of GCD II, we assayed antioxidant enzymes, oxidative damage, and susceptibility to reactive oxygen species-induced cell death in primary cultured corneal fibroblasts (PCFs) from GCD II patients and healthy subjects. We found elevated protein levels of Mn-superoxide dismutase, Cu/Zn-superoxide dismutase, glutathione peroxidase, and glutathione reductase, as well as increased CAT mRNA and decreased catalase protein in GCD II PCFs. Furthermore, catalase is down-regulated in normal PCFs transfected with transforming growth factor-beta-induced gene-h3. We also observed an increase in not only intracellular reactive oxygen species and H(2)O(2) levels, but also malondialdehyde, 4-hydroxynonenal, and protein carbonyls levels in GCD II PCFs. Greater immunoreactivity for malondialdehyde was observed in the corneal tissue of GCD II patients. In addition, we observed a decrease in Bcl-2 and Bcl-xL levels and an increase in Bax and Bok levels in GCD II PCFs. Finally, GCD II PCFs are more susceptible to H(2)O(2)-induced cell death. Together, these results suggest that oxidative damage induced by decreased catalase is involved in GCD II pathogenesis, and antioxidant agents represent a possible treatment strategy.
American Journal Of Pathology 08/2009; 175(1):248-61. · 4.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Poly(vinylidene fluoride) (PVDF) membranes were surface-modified using fluorotelemer intermediate Zonyl BA-L as a fluorinated surface modifying macromolecules (SMM) additives in the concentration range from 0 to 2wt.%. Prepared membranes were characterized by contact angle measurement, electron spectroscopy for chemical analysis (ESCA), scanning electron microscopy (SEM), and pervaporation test. The experimental results showed that SMM migrated to the surface and effectively increased the surface hydrophobicity of the PVDF membranes. The pure water permeation flux evaluated by pervaporation decreased with an increase in the content of SMM.
Journal of Industrial and Engineering Chemistry - J IND ENG CHEM. 01/2009; 15(3):393-397.
[show abstract][hide abstract] ABSTRACT: Microporous asymmetric PVDF hollow fiber membranes were prepared from commercially available polyvinylidenefluoride and N,N-dimethylacetamide (DMAc) by the dry-jet wet phase inversion process. Lithium chloride and water were used as additives. Mean pores size and effective surface porosity were evaluated by the gas permeation method. The membrane morphology was examined with help of scanning electron microscope. PVDF hydrophobic membranes were tested for the absorption of NO2. A series of experiments were performed in a countercurrent mode of operation with gas in the shell side and liquid in the fiber lumen of the module to examine the effect of various operating variables such as module stages, gas and liquid flow rate, concentration of inlet NO2 gas, concentration of absorbent, and nature of absorbent on the NO2 removal efficiency using PVDF HF membranes. The absorption efficiency of aqueous solutions of various chemicals such as Na2SO3, Na2CO3, NaHCO3 and NaOH has been compared and Na2SO3 was found to be the most promising absorbent among them.
[show abstract][hide abstract] ABSTRACT: In the present study, crosslinked poly(vinyl alcohol) (PVA) membranes were prepared using poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA) (PVA:PSSA_MA=1:7). The PSSA_MA was used both as a crosslinking agent and as a donor of the hydrophilic group (–SO3H and/or –COOH). The hybrid membranes were prepared by modified clay such as Clay Na+, Clay 30B, and Clay 15A. The thermal, water uptake, proton and methanol transport properties of the hybrid membrane were found to be sensitive to the clay type and content. The hybrid membrane with Clay 30B shows higher proton conductivity than other hybrid membranes due to hydroxyethyl group. The membrane with Clay 15A showed the lowest methanol permeability due to lower specific gravity than other clay. Compared to the membrane without modified, the PVA/PSSA_MA/Clay 15A containing 4wt% of Clay 15A showed both high proton conductivity (0.023S/cm) and low methanol permeability (2.19×10−7cm2/s).
Journal of Industrial and Engineering Chemistry - J IND ENG CHEM. 01/2009; 15(2):265-269.
[show abstract][hide abstract] ABSTRACT: Conjunctival epithelial cells serve as a first line of defense against pathogens presented to the innate immune system. The inflammatory response to Gram-negative bacteria is initiated by toll-like receptor 4 (TLR4). This study investigated whether a TLR4 ligand induces production of inflammatory cytokines in human conjunctival epithelial cells (HCECs) through nuclear factor kappa-B (NF-kappaB). HCECs were evaluated for TLR4 expression by reverse transcriptase-polymerase chain reaction, Western blot analysis, and flow cytometric analysis. HCECs were stimulated with various concentrations of lipopolysaccharide (LPS) and the innate immune response was quantified by measuring expression of the inflammatory cytokines IL-6 and IL-8. Functional NF-kappaB activation was examined using a luciferase reporter assay. Expression of TLR4-specific mRNA as well as its corresponding protein was observed in HCECs. Surface and intracellular expression of TLR4 was observed in flow cytometric analysis. Incubation of HCECs with LPS led to secretion of IL-6 and IL-8. Blockade of TLR4- and TNFR-associated factor (TRAF) 6 activity abolished LPS-induced inflammatory response in HCECs and incubation of HCECs with LPS led to activation of the NF-kappaB transcription factor. LPS did not enhance the TLR4 expression at both mRNA and protein levels in HCECs. Our results demonstrate that surface expression of TLR4 in HCECs can elicit a TLR4-mediated innate immune response through TRAF6-NF-kappaB and contribute to an inflammatory environment on the ocular surface.
Experimental Eye Research 11/2008; 88(1):49-56. · 3.03 Impact Factor